The present invention relates generally to the field of transmissions, and more particularly to an improved transmission and shift mechanism for a motor vehicle.
Manual transmissions of the type including a lay shaft are well known in the art. Such transmissions are often utilized in connection with high performance automobiles, such as those used in connection with professional racing. In this regard, to facilitate quicker acceleration from a rolling start and to minimize the power necessary to accelerate the automobile, it is also known to use a reduction or drop gear on the lay shaft of the transmission in order to increase the rotational speed of the gear train within the transmission.
Manually shifting gears within transmissions of this type under the rigors of racing conditions, however, is frequently problematic due to the inability to precisely control the disengagement of one set of gears before engagement a second set of gears. For example, in a conventional 4-speed manual transmission, it is known to utilize a shift mechanism wherein a first shift fork is connected to and moves a first clutch ring or synchromesh unit to engage a first or second speed driven gear, and a second shift fork is connected to and moves a second clutch ring or synchromesh unit to engage a third or fourth speed driven gear of the transmission. However, such conventional shift mechanisms do not generally preclude engagement of the third or fourth speed gears while the first or second speed gears are still engaged, or vice versa, which simultaneous engagement may cause significant damage to the components of the transmission.
In addition, once damaged, these conventional transmissions do not readily provide ease in which to replace damaged components (such as gears situated on the lay shaft). Accordingly, significant effort and expense is often required in repairing or replacing such damaged transmissions.
In accordance with the present invention there is provided an embodiment comprising: a gear selecting lever mounted in a casing located external to a transmission housing, a first shift rail operatively connected to the gear selecting lever, a second shift rail operatively connected to the gear selecting lever, and the first and second shift rails including first and second lock-out detents.
In accordance with the present invention there is provided an embodiment comprising: a gear selecting lever mounted in a casing located external to a transmission housing, a first and second rail engagement ends operatively connected to the gear selecting lever and located in a chamber of the casing; a first and second shift rails operatively connected to the first and second rail engagement ends; and a viscous liquid surrounding the rail engagement ends.
In accordance with the present invention there is provided an embodiment comprising: a gear selecting lever mounted in a casing located external to a transmission housing, first and second shift rails operatively connected to the gear selecting lever; and a first plunger to control movement of the gear selecting lever.